scholarly journals Efficacy of Moringa oleifera Seed Husk as Adsorptive Agent for Trihalomethanes from a Water Treatment Plant in Southwestern, Nigeria

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Aderonke Adetutu Okoya ◽  
Olasunkanmi Olalekan Olaiya ◽  
Abimbola Bankole Akinyele ◽  
Nnenneh Oruada Ochor
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Surface Water ◽  
Contact Time ◽  
Moringa Oleifera ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Seed Husk

Trihalomethanes (THMs) are formed when excess chlorine during chlorination of water reacts with organic material in water. They have mutagenic and carcinogenic properties. Moringa oleifera (MO) has found wide acceptance by many people in Nigeria who have used it for food for both humans and fauna, for health purposes, and as a coagulant for water treatment. However, the seed husks are currently discarded as waste and they have not been used as adsorbent to remove THMs from water. The physicochemical properties of both the treated and raw surface water were determined using standard methods, and the concentration of THMs was determined from the water treatment plant at different stages of treatment using gas chromatography with flame ionization detector (GC-FID). Recovery experiments were carried out to validate the procedure. The efficiencies of activated carbon of Moringa oleifera seed husk (MOSH) adsorbent for the removal of THMs in the water and as a coagulant for water treatment were also assessed. Batch adsorption experiments were carried out, and different parameters such as pH (5, 7, and 9), adsorbent dosage (0.2, 0.4, and 0.8 g), contact time (30, 60, and 90 minutes), and initial concentration (0.2, 0.4, and 0.6 mg/l) were optimized for the removal of trichloromethane and tribromomethane using the MOSH activated carbon. Experimental adsorption data from different initial concentrations of trichloromethane and tribromomethane were used to test conformity with Langmuir and Freundlich adsorption isotherms. The percentage recovery from our procedures ranged from 96.0 ± 1.41 to 100.0 ± 0.00 for trichloromethane while for tribromomethane the range was 60 ± 2.82 to 100.0 ± 0.00. The mean percentage adsorption efficiencies for the simulation experiment ranged from 34.365 ± 1.41 to 93.135 ± 0.57 and from 41.870 ± 0.27 to 94.655 ± 0.41 for trichloromethane and tribromomethane, respectively. The optimum conditions for both trichloromethane and tribromomethane were pH 9, 0.8 g adsorbent dosage, 60-minute contact time, and 0.6 mg/l initial concentration. The optimum values of these parameters used for the adsorption of the two THMs in the surface water serving the treatment plant gave an efficiency of 100.00 ± 0.00%. The turbidity values for the coagulation experiment reduced from 9.76 ± 0.03 NTU in the raw water before coagulation to 5.92 ± 0.13 NTU after coagulation while all other physicochemical parameters of the surface water decreased in value except conductivity and total dissolved solid which increased from 104.5 ± 3.54 to 108.0 ± 2.83 μS/cm and 63.00 ± 11.31 to 83.0 ± 8.49 mg/l, respectively. The experimental data best fit into Langmuir than Freundlich adsorption isotherm. The study concluded that MOSH activated carbon could serve as an adsorbent for the removal of THMs, calcium, and sulphur from water samples.

scholarly journals Sorption Characteristics of Halogenated Acetonitriles (HANs) in Surface Water onto Activated Carbon Prepared from Walnut Shell

2020 ◽  
pp. 273-287
Author(s):  
Aderonke Adetutu, Okoya ◽  
Raliat Modupeola Anjous – Alao ◽  
Kehinde Nurudeen Awokoya
Keyword(s):  
Activated Carbon ◽  
Surface Water ◽  
Contact Time ◽  
Treatment Plant ◽  
Walnut Shell ◽  
Batch Adsorption ◽  
Adsorption Efficiency ◽  
Sorption Data ◽  
Experimental Procedure ◽  
Adsorbent Dosage

Sorption efficiencies of activated carbon prepared from walnut shell for the removal of Halogenated Acetonitriles (HANs) from surface water was investigated in this study, as an ethically sound-way of utilizing this unexploited abundant natural resource, and was also compared with burgoyne commercial activated carbon (BCAC). Major HANs created during the disinfection process consist of dichloroacetonitrile (DCAN) and bromoacetonitrile, (BCAN). Physicochemical properties of both raw and chlorinated water were determined using standard methods, and concentration of DCAN were determined from water treatment plant at different stages of treatment using High Performance liquid Chromatography (HPLC). Recovery experiments were carried out to validate experimental procedure. Batch adsorption experiments were carried out and different parameters such as adsorbent dosage (0.2, 0.4, 0.8 g), contact time (30, 60, 90 minutes), pH (5, 7, 9), and concentration (0.006 mg/L, 0.009 mg/L and 0.012 mg/L) were optimized for removal of DCAN using walnut shell activated carbon (WSAC). Experimental sorption data from different initial concentrations of DCAN were used to test conformity with Freundlich and Langmuir adsorption isotherms. Percentage recovery from experimental procedure is 86.01±0.62 to 100.0±0.00 for DCAN. Mean percentage adsorption efficiencies for simulation experiment is 16.670±0.467 to 41.67±1.103 for DCAN. Optimum conditions for DCAN were 0.8g adsorbent dosage, 60 minutes contact time, pH 9 and 0.012 mg/L initial concentration. Optimum values of theses parameters used for adsorption of DCAN in raw and chlorinated water serving the treatment plant gave an adsorption efficiency of 69.00±1.43% and 79.00±0.03 respectively. Adsorption efficiency of BCAC gave 94.4±0.42 and 98.00±1.41 for raw and chlorinated water respectively, with a total decrease in all physicochemical parameters examined after adsorption experiment. Adsorption isotherm studies indicated that Langmuir model was more suitable for the experimental data than Freundlich isotherm model. Conclusively, the effective adsorbent properties displayed by WSAC in the removal of DCAN indicate its potentials in treatment of water contaminations.

scholarly journals Conventional Treatment of Surface Water Using Moringa Oleifera Seeds Extract as a Primary Coagulant

1970 ◽  
Vol 5 (1) ◽  
Author(s):  
Suleyman A. Muyibi, Ahmed Hissein M Birima, Thamer A. Mohammed ◽  
Megat Johari M. M. Noor
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Moringa Oleifera ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Unit Operations ◽  
High Turbidity ◽  
Effective Doses ◽  
Filter Test

The present study involved the use of a model pilot scale water treatment plant to treat turbid surface water from a stream using processed Moringa oleifera seed with 25 % w/w oil extracted as primary coagulant. The water treatment plant was made up of four unit operations: coagulation, flocculation, sedimentation, and filtration (rapid sand filter). Test runs were carried out for three hours per run over a three-month period with turbidities ranging from 18 to 261 NTU. The turbidity, pH, and alkalinity as well as the filter head loss were measured every 30 minutes during the experimental runs. Average turbidity removal of up to 96 % at an effective doses of 20 and 30 mg/l of oil extracted M. oleifera for low (< 50 NTU) and moderate turbidity (< 100 NTU) water respectively was observed doses 50 – 80 mg/l for high turbidity (> 100 NTU) water. M. oleifera seed extract was found to have no significant effect on pH or alkalinity of the water. The residual turbidities measured during most of the test runs satisfied the Malaysian Guideline for Drinking Water Supplies. Key Words: Moringa oleifera, primary coagulant, coagulation, pilot plant, filtration.

scholarly journals Pilot study of the removal of individual trihalomethanes (THMs) from chlorinated drinking water by GAC adsorption - Galatsi water treatment plant, Athens, Greece

2013 ◽  
Vol 15 (4) ◽  
pp. 504-512
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Pilot Study ◽  
Contact Time ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Carbon Surface ◽  
Chlorinated Drinking Water ◽  
Adsorbed Mass

<p>The objective of this pilot study was to evaluate the performance of Powdered Activated Carbon (PAC) for the removal of individual trihalomethanes (THMs) from chlorinated drinking water, Athens, Greece. The pilot treatment facility was located at the Water Treatment Plant of EYDAP (Athens Water Supply and Sewerage Company) in Galatsi, Athens, and consisted of two mixing tanks operating as open batch reactors, which were fed with chlorinated water from the overflow of the sedimentation tanks. Experimental cycles were performed, with different PAC doses ranging from 5 to 50 mg L-1 and with contact times 30 and 60 min for each cycle. Water samples taken at the start of each cycle and after contact with PAC, were analysed for individual THMs and Dissolved Organic Carbon (DOC). Bromide, free residual chlorine, pH and temperature were also measured. From the experimental results, it was shown that all THMs concentrations were decreased after PAC contact, the decrease being higher for higher PAC dose and higher contact time, with few exceptions. This fact probably indicates that adsorption rate plus volatilisation rate of THMs overcame formation rate, in most cases. It was also concluded that volatilisation and possible formation reactions of THMs had probably a more apparent effect to the total removal of most THMs at low PAC doses and low contact time. At higher PAC doses and higher contact time, PAC adsorption probably had an increased contribution to THMs removal, because of the larger carbon surface area and the longer contact time, resulting in higher adsorbed mass according to adsorption theory. By using isotherm results of individual THMs on activated carbon by other researchers, the theoretically adsorbed mass of THMs per g of PAC was roughly estimated and compared with the measured removed mass of THMs per g of PAC at PAC dose 50 mg L-1 and contact time 60 min for most THMs, on the assumption of equilibrium achievement. The removed mass of THMs by PAC appeared much higher than the theoretically adsorbed, especially for the most volatile members. The difference was attributed to volatilisation taking place in the open mixing tanks. In conclusion, the practical results from the application of PAC for the removal of THMs are much better than expected from single adsorption by PAC. Volatility of THMs, especially of chloroform (TCM), substitutes for weak adsorbability and gives increased removal. The influent DOC was almost constant in all experiments. The removal of DOC was generally higher for increased PAC dose and contact time. Although equilibration cannot have happened for DOC, the mass removal of DOC per g of PAC was higher by more than two orders of size than that of the smaller and in lower concentration THMs, as expected.</p>

Cost-effective water treatment of polluted surface water by using direct filtration and granular activated carbon filtration

2002 ◽  
Vol 2 (1) ◽  
pp. 233-240 ◽  
Author(s):  
J. Cromphout ◽  
W. Rougge
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Process ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Direct Filtration ◽  
Carbon Filtration ◽  
Effective Water

In Harelbeke a Water Treatment Plant with a capacity of 15,000 m3/day, using Schelde river water has been in operation since April 1995. The treatment process comprises nitrification, dephosphatation by direct filtration, storage into a reservoir, direct filtration, granular activated carbon filtration and disinfection. The design of the three-layer direct filters was based on pilot experiments. The performance of the plant during the five years of operation is discussed. It was found that the removal of atrazin by activated carbon depends on the water temperature.

Practical Guide to Determine the Impact of Radon and Other Radionuclides on Water Treatment Processes

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Packed Tower ◽  
Treatment Processes ◽  
Radioactivity Exposure ◽  
The Impact ◽  
Percent Removal

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.

scholarly journals The Efficiency of Microstrainers Filtration in the Process of Removing Phytoplankton with Special Consideration of Cyanobacteria

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 285 ◽  
Author(s):  
Wanda Czyżewska ◽  
Marlena Piontek
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Filtration Process ◽  
Particle Filtration ◽  
Qualitative And Quantitative ◽  
Water Treatment Process ◽  
Adverse Impacts ◽  
Quantitative Monitoring

The research presented in this manuscript concerns the evaluation of the effectiveness of microstrainers, which are designed to reduce the amount of plankton in treated surface water. The efficiency of microstrainer filtration analysis is very important for the proper course of the water-treatment process not only in the Water-Treatment Plant (WTP) in Zielona Góra (central western Poland) but also in other WTPs around the world. The qualitative and quantitative monitoring of the abundance of plankton including cyanobacteria during the particle-filtration process allows not only for the assessment of the potential cyanotoxic risk in surface water providing a source of drinking water, but also allows the evaluation of the action and the prevention of adverse impacts of microstrainers. Over four years of research, it was observed that the largest amount of cyanobacteria before microstrainer filtration took place in May. The dominant species was Limnothrix redeckei. The microstrainer removal of plankton and cyanobacteria was statistically significant. The quantity of removed plankton increased with its increasing content in raw water. The particle-filtration process, by reducing the amount of cyanobacteria, contributes to a decrease in intracellular microcystins.

scholarly journals Pesticide removals in the nitrifying expanded-bed filter at drinking water treatment plant

2020 ◽  
Vol 15 (1) ◽  
pp. 1-13
Author(s):  
Nguyet Thi-Minh Dao ◽  
The-Anh Nguyen ◽  
Viet-Anh Nguyen ◽  
Mitsuharu Terashima ◽  
Hidenari Yasui
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Field Analysis ◽  
Expanded Bed ◽  
Biological Activated Carbon

The occurrence of pesticides even at low concentrations in drinking water sources might induce potential risks to public health. This study aimed to investigate the removal mechanisms of eight pesticides by the nitrifying expanded-bed filter using biological activated carbon media at the pretreatment of a drinking water plant. The field analysis demonstrated that four pesticides Flutolanil, Buprofezin, Chlorpyrifos, and Fenobucard, were removed at 82%, 55%, 54%, and 52% respectively, while others were not significantly removed. Under controlled laboratory conditions with continuous and batch experiments, the adsorption onto the biological activated carbon media was demonstrated to be the main removal pathway of the pesticides. The contribution of microorganisms to the pesticide removals was rather limited. The pesticide removals observed in the field reactor was speculated to be the adsorption on the suspended solids presented in the influent water. The obtained results highlighted the need to apply a more efficient and cost-effective technology to remove the pesticide in the drinking water treatment process. Keywords: biological activated carbon; drinking water treatment; nitrifying expanded-bed filter; pesticide removal.

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